2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Control flow optimizations.
23 * @author Goetz Lindenmaier, Michael Beck, Sebastian Hack
28 #include "iroptimize.h"
35 #include "irgraph_t.h"
49 #include "irbackedge_t.h"
54 #include "iropt_dbg.h"
56 /*------------------------------------------------------------------*/
57 /* Control flow optimization. */
59 /* Removes Bad control flow predecessors and empty blocks. A block */
60 /* is empty if it contains only a Jmp node. */
61 /* Blocks can only be removed if they are not needed for the */
62 /* semantics of Phi nodes. */
63 /* Further, we NEVER remove labeled blocks (even if we could move */
65 /*------------------------------------------------------------------*/
67 #define set_Block_removable(block) set_Block_mark(block, 1)
68 #define set_Block_non_removable(block) set_Block_mark(block, 0)
69 #define is_Block_removable(block) (get_Block_mark(block) != 0)
72 * Replace binary Conds that jumps twice into the same block
78 * ProjX True ProjX False ==> | /
83 * Such pattern are the result of if-conversion.
85 * Note that the simple case that Block has only these two
86 * predecessors are already handled in equivalent_node_Block().
88 static int remove_senseless_conds(ir_node *bl) {
90 int n = get_Block_n_cfgpreds(bl);
93 for (i = 0; i < n; ++i) {
94 ir_node *pred_i = get_Block_cfgpred(bl, i);
95 ir_node *cond_i = skip_Proj(pred_i);
98 if (is_Cond(cond_i) && get_irn_mode(get_Cond_selector(cond_i)) == mode_b) {
100 for (j = i + 1; j < n; ++j) {
101 ir_node *pred_j = get_Block_cfgpred(bl, j);
102 ir_node *cond_j = skip_Proj(pred_j);
104 if (cond_j == cond_i) {
105 ir_node *jmp = new_r_Jmp(current_ir_graph, get_nodes_block(cond_i));
106 set_irn_n(bl, i, jmp);
107 set_irn_n(bl, j, new_Bad());
109 DBG_OPT_IFSIM2(cond_i, jmp);
119 /** An environment for merge_blocks and collect nodes. */
120 typedef struct _merge_env {
121 int changed; /**< Set if the graph was changed. */
122 int phis_moved; /**< Set if Phi nodes were moved. */
123 plist_t *list; /**< Helper list for all found Switch Conds. */
127 * Removes Tuples from Block control flow predecessors.
128 * Optimizes blocks with equivalent_node(). This is tricky,
129 * as we want to avoid nodes that have as block predecessor Bads.
130 * Therefore we also optimize at control flow operations, depending
131 * how we first reach the Block.
133 static void merge_blocks(ir_node *node, void *ctx) {
136 merge_env *env = ctx;
138 /* clear the link field for ALL nodes first */
139 set_irn_link(node, NULL);
141 if (is_Block(node)) {
143 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
144 ir_node *pred = get_Block_cfgpred(node, i);
145 ir_node *skipped = skip_Tuple(pred);
146 if (pred != skipped) {
147 set_Block_cfgpred(node, i, skipped);
153 new_block = equivalent_node(node);
154 if (new_block != node && ! is_Block_dead(new_block)) {
155 exchange(node, new_block);
159 } else if (get_opt_optimize() && (get_irn_mode(node) == mode_X)) {
160 /* We will soon visit a block. Optimize it before visiting! */
161 ir_node *b = get_nodes_block(skip_Proj(node));
163 if (!is_Block_dead(b)) {
164 new_block = equivalent_node(b);
166 while (!irn_visited(b) && !is_Block_dead(new_block) && new_block != b) {
167 /* We would have to run gigo() if new is bad, so we
168 promote it directly below. Nevertheless, we sometimes reach a block
169 the first time through a dataflow node. In this case we optimized the
170 block as such and have to promote the Bad here. */
171 assert((get_opt_control_flow_straightening() ||
172 get_opt_control_flow_weak_simplification()) &&
173 ("strange flag setting"));
174 exchange(b, new_block);
177 new_block = equivalent_node(b);
180 /* normally, we would create a Bad block here, but this must be
181 * prevented, so just set it's cf to Bad.
183 if (is_Block_dead(new_block)) {
184 exchange(node, new_Bad());
192 * Block walker removing control flow from dead block by
193 * inspecting dominance info.
194 * Do not replace blocks by Bad. This optimization shall
195 * ensure, that all Bad control flow predecessors are
196 * removed, and no new other Bads are introduced.
197 * Further removed useless Conds and clear the mark of all blocks.
199 * Must be run in the post walker.
201 static void remove_unreachable_blocks_and_conds(ir_node *block, void *env) {
205 /* Check block predecessors and turn control flow into bad.
206 Beware of Tuple, kill them. */
207 for (i = get_Block_n_cfgpreds(block) - 1; i >= 0; --i) {
208 ir_node *pred_X = get_Block_cfgpred(block, i);
209 ir_node *skipped = skip_Tuple(pred_X);
211 if (! is_Bad(skipped)) {
212 ir_node *pred_bl = get_nodes_block(skip_Proj(skipped));
214 if (is_Block_dead(pred_bl) || (get_Block_dom_depth(pred_bl) < 0)) {
215 set_Block_dead(pred_bl);
216 exchange(pred_X, new_Bad());
218 } else if (skipped != pred_X) {
219 set_Block_cfgpred(block, i, skipped);
225 *changed |= remove_senseless_conds(block);
227 /* clear the block mark of all blocks */
228 set_Block_removable(block);
232 * Collects all Phi nodes in link list of Block.
233 * Marks all blocks "non_removable" if they contain a node other
234 * than Jmp (and Proj).
235 * Links all Proj nodes to their predecessors.
236 * Collects all switch-Conds in a list.
238 static void collect_nodes(ir_node *n, void *ctx) {
239 ir_opcode code = get_irn_opcode(n);
240 merge_env *env = ctx;
242 if (code == iro_Block) {
243 /* mark the block as non-removable if it is labeled */
244 if (has_Block_label(n))
245 set_Block_non_removable(n);
247 ir_node *b = get_nodes_block(n);
249 if (code == iro_Phi && get_irn_arity(n) > 0) {
250 /* Collect Phi nodes to compact ins along with block's ins. */
251 set_irn_link(n, get_irn_link(b));
253 } else if (code != iro_Jmp && !is_Bad(b)) { /* Check for non-empty block. */
254 set_Block_non_removable(b);
256 if (code == iro_Proj) { /* link Proj nodes */
257 ir_node *pred = get_Proj_pred(n);
259 set_irn_link(n, get_irn_link(pred));
260 set_irn_link(pred, n);
261 } else if (code == iro_Cond) {
262 ir_node *sel = get_Cond_selector(n);
263 if (mode_is_int(get_irn_mode(sel))) {
264 /* found a switch-Cond, collect */
265 plist_insert_back(env->list, n);
272 /** Returns true if pred is predecessor of block. */
273 static int is_pred_of(ir_node *pred, ir_node *b) {
276 for (i = get_Block_n_cfgpreds(b) - 1; i >= 0; --i) {
277 ir_node *b_pred = get_Block_cfgpred_block(b, i);
284 /** Test whether we can optimize away pred block pos of b.
286 * @param b A block node.
287 * @param pos The position of the predecessor block to judge about.
289 * @returns The number of predecessors
291 * The test is rather tricky.
293 * The situation is something like the following:
302 * b merges the control flow of an if-then-else. We may not remove
303 * the 'then' _and_ the 'else' block of an 'if' if there is a Phi
304 * node in b, even if both are empty. The destruction of this Phi
305 * requires that a copy is added before the merge. We have to
306 * keep one of the case blocks to place the copies in.
308 * To perform the test for pos, we must regard predecessors before pos
309 * as already removed.
311 static int test_whether_dispensable(ir_node *b, int pos) {
312 int i, j, n_preds = 1;
313 ir_node *pred = get_Block_cfgpred_block(b, pos);
315 /* Bad blocks will be optimized away, so we don't need space for them */
316 if (is_Block_dead(pred))
319 if (is_Block_removable(pred)) {
320 if (!get_opt_optimize() || !get_opt_control_flow_strong_simplification()) {
321 /* Mark block so that is will not be removed: optimization is turned off. */
322 set_Block_non_removable(pred);
326 /* Seems to be empty. At least we detected this in collect_nodes. */
327 if (get_irn_link(b) == NULL) {
328 /* There are no Phi nodes ==> all predecessors are dispensable. */
329 n_preds = get_Block_n_cfgpreds(pred);
331 /* b's pred blocks and pred's pred blocks must be pairwise disjunct.
332 Handle all pred blocks with preds < pos as if they were already removed. */
333 for (i = 0; i < pos; i++) {
334 ir_node *b_pred = get_Block_cfgpred_block(b, i);
335 if (! is_Block_dead(b_pred) && is_Block_removable(b_pred)) {
336 for (j = get_Block_n_cfgpreds(b_pred) - 1; j >= 0; --j) {
337 ir_node *b_pred_pred = get_Block_cfgpred_block(b_pred, j);
338 if (is_pred_of(b_pred_pred, pred))
339 goto non_dispensable;
342 if (is_pred_of(b_pred, pred))
343 goto non_dispensable;
346 for (i = pos +1; i < get_Block_n_cfgpreds(b); i++) {
347 ir_node *b_pred = get_Block_cfgpred_block(b, i);
348 if (is_pred_of(b_pred, pred))
349 goto non_dispensable;
351 /* if we get here, the block is dispensable */
352 n_preds = get_Block_n_cfgpreds(pred);
359 set_Block_non_removable(pred);
364 * This method removed Bad cf predecessors from Blocks and Phis, and removes
365 * empty blocks. A block is empty if it only contains Phi and Jmp nodes.
367 * We first adapt Phi nodes, then Block nodes, as we need the old ins
368 * of the Block to adapt the Phi nodes. We do this by computing new
369 * in arrays, and then replacing the old ones. So far we compute new in arrays
370 * for all nodes, not regarding whether there is a possibility for optimization.
372 * For each predecessor p of a Block b there are three cases:
373 * -1. The predecessor p is a Bad node: just skip it. The in array of b shrinks by one.
374 * -2. The predecessor p is empty. Remove p. All predecessors of p are now
376 * -3. The predecessor p is a block containing useful code. Just keep p as is.
378 * For Phi nodes f we have to check the conditions at the Block of f.
379 * For cases 1 and 3 we proceed as for Blocks. For case 2 we can have two
381 * -2a: The old predecessor of the Phi f is a Phi pred_f IN THE BLOCK REMOVED. In this
382 * case we proceed as for blocks. We remove pred_f. All
383 * predecessors of pred_f now are predecessors of f.
384 * -2b: The old predecessor of f is NOT in the block removed. It might be a Phi, too.
385 * We have to replicate f for each predecessor of the removed block. Or, with
386 * other words, the removed predecessor block has exactly one predecessor.
388 * Further there is a special case for self referencing blocks:
391 * then_b else_b then_b else_b
397 * | | | === optimized to ===> \ | | |
404 * If there is a Phi in pred_b, but we remove pred_b, we have to generate a
405 * Phi in loop_b, that has the ins of the Phi in pred_b and a self referencing
407 * @@@ It is negotiable whether we should do this ... there might end up a copy
408 * from the Phi in the loop when removing the Phis.
410 static void optimize_blocks(ir_node *b, void *ctx) {
411 int i, j, k, n, max_preds, n_preds, p_preds = -1;
412 ir_node *pred, *phi, *next;
414 merge_env *env = ctx;
416 /* Count the number of predecessor if this block is merged with pred blocks
419 for (i = 0, k = get_Block_n_cfgpreds(b); i < k; ++i) {
420 max_preds += test_whether_dispensable(b, i);
422 in = XMALLOCN(ir_node*, max_preds);
424 /*- Fix the Phi nodes of the current block -*/
425 for (phi = get_irn_link(b); phi != NULL; phi = next) {
427 next = get_irn_link(phi);
429 /* Find the new predecessors for the Phi */
431 for (i = 0, n = get_Block_n_cfgpreds(b); i < n; ++i) {
432 pred = get_Block_cfgpred_block(b, i);
434 if (is_Block_dead(pred)) {
435 /* case Phi 1: Do nothing */
436 } else if (is_Block_removable(pred) && !Block_block_visited(pred)) {
437 /* case Phi 2: It's an empty block and not yet visited. */
438 ir_node *phi_pred = get_Phi_pred(phi, i);
440 for (j = 0, k = get_Block_n_cfgpreds(pred); j < k; j++) {
441 /* because of breaking loops, not all predecessors are Bad-clean,
442 * so we must check this here again */
443 if (! is_Bad(get_Block_cfgpred(pred, j))) {
444 if (get_nodes_block(phi_pred) == pred) {
446 assert(is_Phi(phi_pred)); /* Block is empty!! */
448 in[p_preds++] = get_Phi_pred(phi_pred, j);
451 in[p_preds++] = phi_pred;
457 in[p_preds++] = get_Phi_pred(phi, i);
460 assert(p_preds <= max_preds);
464 /* By removal of Bad ins the Phi might be degenerated. */
465 exchange(phi, in[0]);
467 set_irn_in(phi, p_preds, in);
471 /*- This happens only if merge between loop backedge and single loop entry.
472 Moreover, it is only needed if predb is the direct dominator of b, else there can be no uses
473 of the Phi's in predb ... -*/
474 for (k = 0, n = get_Block_n_cfgpreds(b); k < n; ++k) {
475 ir_node *predb = get_nodes_block(get_Block_cfgpred(b, k));
477 if (is_Block_removable(predb) && !Block_block_visited(predb)) {
480 /* we found a predecessor block at position k that will be removed */
481 for (phi = get_irn_link(predb); phi; phi = next_phi) {
483 next_phi = get_irn_link(phi);
487 if (get_Block_idom(b) != predb) {
488 /* predb is not the dominator. There can't be uses of pred's Phi nodes, kill them .*/
489 exchange(phi, new_Bad());
491 /* predb is the direct dominator of b. There might be uses of the Phi nodes from
492 predb in further block, so move this phi from the predecessor into the block b */
493 set_nodes_block(phi, b);
494 set_irn_link(phi, get_irn_link(b));
495 set_irn_link(b, phi);
498 /* first, copy all 0..k-1 predecessors */
499 for (i = 0; i < k; i++) {
500 pred = get_Block_cfgpred_block(b, i);
502 if (is_Block_dead(pred)) {
504 } else if (is_Block_removable(pred) && !Block_block_visited(pred)) {
505 /* It's an empty block and not yet visited. */
506 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
507 if (! is_Bad(get_Block_cfgpred(pred, j)))
515 /* now we are at k, copy the phi predecessors */
516 pred = get_nodes_block(get_Block_cfgpred(b, k));
517 for (i = 0; i < get_Phi_n_preds(phi); i++) {
518 if (! is_Bad(get_Block_cfgpred(pred, i)))
519 in[q_preds++] = get_Phi_pred(phi, i);
522 /* and now all the rest */
523 for (i = k+1; i < get_Block_n_cfgpreds(b); i++) {
524 pred = get_Block_cfgpred_block(b, i);
526 if (is_Block_dead(pred)) {
528 } else if (is_Block_removable(pred) && !Block_block_visited(pred)) {
529 /* It's an empty block and not yet visited. */
530 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
531 if (! is_Bad(get_Block_cfgpred(pred, j)))
541 exchange(phi, in[0]);
543 set_irn_in(phi, q_preds, in);
546 assert(q_preds <= max_preds);
547 // assert(p_preds == q_preds && "Wrong Phi Fix");
553 /*- Fix the block -*/
555 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
556 pred = get_Block_cfgpred_block(b, i);
558 if (is_Block_dead(pred)) {
559 /* case 1: Do nothing */
560 } else if (is_Block_removable(pred) && !Block_block_visited(pred)) {
561 /* case 2: It's an empty block and not yet visited. */
562 assert(get_Block_n_cfgpreds(b) > 1);
563 /* Else it should be optimized by equivalent_node. */
564 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
565 ir_node *pred_X = get_Block_cfgpred(pred, j);
567 /* because of breaking loops, not all predecessors are Bad-clean,
568 * so we must check this here again */
569 if (! is_Bad(pred_X))
570 in[n_preds++] = pred_X;
572 /* Remove block as it might be kept alive. */
573 exchange(pred, b/*new_Bad()*/);
576 in[n_preds++] = get_Block_cfgpred(b, i);
579 assert(n_preds <= max_preds);
581 set_irn_in(b, n_preds, in);
584 assert(get_irn_link(b) == NULL || p_preds == -1 || (n_preds == p_preds && "Wrong Phi Fix"));
589 * Block walker: optimize all blocks using the default optimizations.
590 * This removes Blocks that with only a Jmp predecessor.
592 static void remove_simple_blocks(ir_node *block, void *ctx) {
593 ir_node *new_blk = equivalent_node(block);
594 merge_env *env = ctx;
596 if (new_blk != block) {
597 exchange(block, new_blk);
603 * Handle pre-optimized table switch Cond's.
604 * During iropt, all Projs from a switch-Cond are already removed except
605 * the defProj and maybe the taken one.
606 * The defProj cannot be removed WITHOUT looking backwards, so we do this here.
608 * @param cond the switch-Cond
610 * @return non-zero if a switch-Cond was optimized
612 * Expects all Proj's linked to the cond node
614 static int handle_switch_cond(ir_node *cond) {
615 ir_node *sel = get_Cond_selector(cond);
617 ir_node *proj1 = get_irn_link(cond);
618 ir_node *proj2 = get_irn_link(proj1);
621 blk = get_nodes_block(cond);
624 /* this Cond has only one Proj: must be the defProj */
625 assert(get_Cond_defaultProj(cond) == get_Proj_proj(proj1));
626 /* convert it into a Jmp */
627 jmp = new_r_Jmp(current_ir_graph, blk);
628 exchange(proj1, jmp);
630 } else if (get_irn_link(proj2) == NULL) {
631 /* We have two Proj's here. Check if the Cond has
632 a constant argument */
633 tarval *tv = value_of(sel);
635 if (tv != tarval_bad) {
636 /* we have a constant switch */
637 long num = get_tarval_long(tv);
638 long def_num = get_Cond_defaultProj(cond);
640 if (def_num == get_Proj_proj(proj1)) {
641 /* first one is the defProj */
642 if (num == get_Proj_proj(proj2)) {
643 jmp = new_r_Jmp(current_ir_graph, blk);
644 exchange(proj2, jmp);
645 exchange(proj1, new_Bad());
648 } else if (def_num == get_Proj_proj(proj2)) {
649 /* second one is the defProj */
650 if (num == get_Proj_proj(proj1)) {
651 jmp = new_r_Jmp(current_ir_graph, blk);
652 exchange(proj1, jmp);
653 exchange(proj2, new_Bad());
657 /* neither: strange, Cond was not optimized so far */
658 if (num == get_Proj_proj(proj1)) {
659 jmp = new_r_Jmp(current_ir_graph, blk);
660 exchange(proj1, jmp);
661 exchange(proj2, new_Bad());
663 } else if (num == get_Proj_proj(proj2)) {
664 jmp = new_r_Jmp(current_ir_graph, blk);
665 exchange(proj2, jmp);
666 exchange(proj1, new_Bad());
675 /* Optimizations of the control flow that also require changes of Phi nodes.
677 * This optimization performs two passes over the graph.
679 * The first pass collects all Phi nodes in a link list in the block
680 * nodes. Further it performs simple control flow optimizations.
681 * Finally it marks all blocks that do not contain useful
682 * computations, i.e., these blocks might be removed.
684 * The second pass performs the optimizations intended by this algorithm.
685 * It walks only over block nodes and adapts these and the Phi nodes in these blocks,
686 * which it finds in a linked list computed by the first pass.
688 * We use the mark flag to mark removable blocks in the first
691 void optimize_cf(ir_graph *irg) {
694 ir_node *cond, *end = get_irg_end(irg);
695 ir_graph *rem = current_ir_graph;
699 assert(get_irg_phase_state(irg) != phase_building);
701 /* if the graph is not pinned, we cannot determine empty blocks */
702 assert(get_irg_pinned(irg) != op_pin_state_floats &&
703 "Control flow optimization need a pinned graph");
705 current_ir_graph = irg;
707 /* FIXME: control flow opt destroys block edges. So edges are deactivated here. Fix the edges! */
708 edges_deactivate(irg);
710 /* we use the mark flag to mark removable blocks */
711 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK);
716 /* ALWAYS kill unreachable control flow. Backend cannot handle it anyway.
717 Use dominator info to kill blocks. Also optimize useless Conds. */
719 irg_block_walk_graph(irg, NULL, remove_unreachable_blocks_and_conds, &env.changed);
721 /* fix the keep-alives */
722 for (i = 0, n = get_End_n_keepalives(end); i < n; ++i) {
723 ir_node *ka = get_End_keepalive(end, i);
726 /* do NOT keep dead blocks */
727 if (is_Block_dead(ka) || get_Block_dom_depth(ka) < 0) {
728 set_End_keepalive(end, i, new_Bad());
731 } else if (is_Block_dead(get_nodes_block(ka)) ||
732 get_Block_dom_depth(get_nodes_block(ka)) < 0) {
733 /* do NOT keep nodes in dead blocks */
734 set_End_keepalive(end, i, new_Bad());
739 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
741 env.list = plist_new();
742 irg_walk(end, merge_blocks, collect_nodes, &env);
744 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
747 /* Handle graph state if was changed. */
748 set_irg_outs_inconsistent(irg);
749 set_irg_doms_inconsistent(irg);
750 set_irg_extblk_inconsistent(irg);
751 set_irg_loopinfo_inconsistent(irg);
755 /* handle all collected switch-Conds */
756 foreach_plist(env.list, el) {
757 cond = plist_element_get_value(el);
758 env.changed |= handle_switch_cond(cond);
760 plist_free(env.list);
763 /* The Cond optimization might generate unreachable code, so restart if
768 /* Optimize the standard code. */
771 irg_block_walk(get_irg_end_block(irg), optimize_blocks, remove_simple_blocks, &env);
773 /* Walk all keep alives, optimize them if block, add to new in-array
774 for end if useful. */
775 n = get_End_n_keepalives(end);
777 NEW_ARR_A(ir_node *, in, n);
779 /* in rare cases a node may be kept alive more than once, use the visited flag to detect this */
780 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
781 inc_irg_visited(irg);
783 /* fix the keep alive */
784 for (i = j = 0; i < n; i++) {
785 ir_node *ka = get_End_keepalive(end, i);
787 if (!irn_visited(ka)) {
789 if (!Block_block_visited(ka)) {
790 /* irg_block_walk() will increase the block visited flag, but we must visit only
791 these blocks that are not visited yet, so decrease it first. */
792 set_irg_block_visited(irg, get_irg_block_visited(irg) - 1);
793 irg_block_walk(ka, optimize_blocks, remove_simple_blocks, &env.changed);
794 mark_irn_visited(ka);
798 mark_irn_visited(ka);
799 /* don't keep alive dead blocks */
800 if (!is_Bad(ka) && !is_Block_dead(get_nodes_block(ka)))
806 set_End_keepalives(end, j, in);
810 ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_IRN_VISITED);
812 if (env.phis_moved) {
813 /* Bad: when we moved Phi's, we might produce dead Phi nodes
815 Some other phases cannot copy with this, so will them.
817 n = get_End_n_keepalives(end);
820 /* Handle graph state if was changed. */
821 set_irg_outs_inconsistent(irg);
823 assure_irg_outs(irg);
825 for (i = j = 0; i < n; ++i) {
826 ir_node *ka = get_End_keepalive(end, i);
831 for (k = get_irn_n_outs(ka) - 1; k >= 0; --k) {
832 ir_node *user = get_irn_out(ka, k);
834 if (user != ka && user != end) {
835 /* Is it a real user or just a self loop ? */
845 set_End_keepalives(end, j, in);
852 /* Handle graph state if was changed. */
853 set_irg_outs_inconsistent(irg);
854 set_irg_doms_inconsistent(irg);
855 set_irg_extblk_inconsistent(irg);
856 set_irg_loopinfo_inconsistent(irg);
860 /* the verifier doesn't work yet with floating nodes */
861 if (get_irg_pinned(irg) == op_pin_state_pinned) {
862 /* after optimize_cf(), only Bad data flow may remain. */
863 if (irg_vrfy_bads(irg, BAD_DF | BAD_BLOCK | TUPLE)) {
864 dump_ir_block_graph(irg, "-vrfy-cf");
865 dump_ir_graph(irg, "-vrfy-cf");
866 fprintf(stderr, "VRFY_BAD in optimize_cf()\n");
870 current_ir_graph = rem;